Bubble cap



H. 'S. DU EY BUBBLE CAP June 22, 1937.

Filed March 23, 1936 I Patented June 22, 1937 UNITED STATES PATENTOFFICE amaze BUBBLE car Application March 23, 1936, Serial No. 70,268

11 Claim.

be positioned to vary the spacing between the lower effective edge ofthe cap and the plate or deck to which it is fastened, and therebypermit individual adjustment of the cap submergence.

I Inthe art to which this invention pertains, it is often necessary toarrange a great number of individual bubble caps on a single plate oflarge diameter, and, to obtain a low pressure drop of the gas passingthrough the caps and the liquid 5 on the plate, the submergence, ordistance to which the lower effective edge of the plate dips into theliquid, is made very small. It is well known that the uniform flow ofliquid across a plate of this nature requires a difference in hydraulichead, and the magnitude of that difference may be such that the caps onone side of theplate, where the liquid is admitted to the plate, may besubmerged too deeply, while those caps on the discharge side may beentirely out of theliquid, thereby by-passing the gas or vapor withoutadequate contact by bubbling through the liquid.

Various plans have been proposed to prevent this action, such as the useof multiple liquid downspouts, liquid pools at various levels, weirs,baflles and the like, but all of these are expensive, bulky and notadapted to free fluid and gas flow.

The expense of making and adjusting caps with risers or supports ofdifferent fixed heights is so great that such an alternative is notpracticable.

This invention, however, comprehends a combination of a bubble cap witha riser of a construction that will permit of easy and accurateindividual'submergence adjustment within wide 6 limits and withoutremoving the assembly from the bubble plate or its enclosure.

Another object is to provide a cap, riser and strongback combinationthat will give a minimum of pressure drop due to gas or vapor flow.

Another object is to provide a bubble cap and riser assembly in whichthe mutually contacting surfaces of said cap and riser are formed with aplurality of spaced seating surfaces, inclined planes, or steps so thatthe spacing between said cap and said riser may be varied by a partialrotation of said cap with regard to said riser.

Another object is to provide a cap, riser and strongbackcombination thatmay be fabricated by a simple casting operation, and that will requireno machine operations other than the usual simple cleaning up.

These and other objects and advantages will be more fully apparent fromthe following description and from the attached drawing, which forms apart of this specification, and illustrates a preferred embodiment ofthis invention.

The drawing is a vertical sectional view through a bubble plate and abubble cap, vapor riser and strongback holding said cap in place in anopening in said plate.-

In the drawing, reference numeral I0 designates a bubble plate, as forexample in a fractionating column. The function of this plate is tosupport a liquid on its upper surface through which a gas or vapor isbubbled or otherwise contacted, the vapor rising through a plurality ofopenings spaced at the desired intervals about the plate l0, one ofwhich openings is indicated at H. 4

A generally cylindrical riser I2 is provided with a circumferentialshoulder l3 at its lower edge, which seats on a gasket I4 surroundingopening I I in plate l0, and thus makes a fluid tight joint at thatpoint. The body of riser I2 is preferably of a reduced diameter ormodified venturi shape indicated at l5, thus taking advantage of thenormal vena contracta path of gas flow through such an opening in aplate, and thereby reducing the pressure drop therethrough. The upperend of riser I2 is preferably formed in a circumferential series ofspaced inclined planes or steps It, usually three in number, on whichthe main cap I1 is adjustably supported, as will be described below. I35 The cap or bell I1 is adapted to fit over the top of riser l2 and tobe centered thereon by a plurality of inwardly directed webs l8, whichmay be stepped as at [9 to seat upon the top of inclined planes It. Intheir preferred form, steps I9 and planes it are relatively smooth inconfiguration, but if it is desired to secure them against thepossibility of accidental dislodgment, small steps, serrations, orinterlocking teeth could readily be provided on either or both, withoutdeparting from the invention.

The lower and outer edge of cap I! may be serrated or notched as at 20or may have any of the customary types of perforations, slots or similarshapes to insure fine division of the gas issuing from beneath the edgeinto the liquid on the plate Ill.

In order to retain riser l2 and cap ll in place in opening H, astrongback 2| preferably is provided, adapted to engage the lower faceof plate l0 asby arms 22, which extend outwardly and terminate inshoulders 23 seating in opening H and being guided by slots 24 in thelower edge of riser l2. Strongback 2| is preferably made oi? skeletonform, with arms 22, in this case three in number, radiating outwardlyand upwardly from a central boss 25, and of such configuration andprojected area as to offer little resistance to vapor flow. Boss 25 maybe centrally bored out Or cored as at 26 to receive a through bolt 21,-the head 28 of the bolt being retained in a squared recess 29 to preventits turning relative to the' strongback 2|.

Cap I1 is also provided with a central hole 30 through which the upperend of bolt 21 passes and to which the cap is secured as by washer 3|and threaded nut 32. The inside of cap 30 may be shaped into a boss asshown at 33, to form a passage of substantially uniform area for thevapor or gas passing up through riser I12 and thence downwardly underthe edge of the cap 11 into the liquid.

The operation and advantages of the assembly, to obtain the desiredvertical spacing of the top of serrations 20 from plate II] are quiteobvious from the drawing. Loosening nut 32 on bolt 2'! permits cap I! tobe turned relative to the riser l2, and steps l9 are adjusted oninclined planes 46, to give the desired spacing between the edge of thecap and the top of plate III, which also is a function of the height ofcap I! above riser l2.

Although a specific construction of a bubble cap assembly is describedand illustrated, it will be understood that many variations may be madefrom the example shown, and all such modifications as come within thescope of the appended claims are embraced thereby.

I claim:

1. A bubble cap assembly comprising a. riser, a cap for said riser, andmutually contacting means on said riser and said cap provided withcircumferentially spaced seating surfaces of such a character that thespacing between said riser and said cap may be varied by a partialrotation of said cap with regard to said riser.

2. A bubble cap assembly according to claim 1 with the addition of meansfor seating said riser over a hole in a plate and means engaging saidplate for holding said cap and said riser in place thereon.

3. A bubble cap assembly according to claim 1 with the addition of means'for seating said riser over a hole in a plate and means engaging saidplate and said riser for holding said cap in place on said riser.

4. A bubble cap assembly adapted to cover an opening in a plate,comprising a generally cylindrical riser adapted to be seated over saidopening, said riser being provided with a plurality of spaced inclinedplanes, a cap for said riser, and. means on said cap adapted to beselectively seated .on said planes to vary the spacing between said capand said plate.

5. A bubble cap assembly according to claim 4 with the addition of meansengageable with said plate to hold said cap and said riser in positionthereon.

6. A bubble cap assembly according to claim 4 with the addition of amember adapted to straddle said opening beneath said riser and meanspassing through said member and said cap for clamping said cap and saidriser to said plate.

7. A bubble cap assembly adapted to cover an opening in a plate,comprising a generally cylindrical riser with a base adapted 'to beseated over said opening, the upper end of said riser being providedwith seating surfaces at varying distances from said base, a cap forsaid riser, and means on said cap adapted to be selectively seated onsaid surfaces of said riser to determine the spacing between said capand the base of said riser.

8. A bubble cap assembly according to claim 7 with the addition of meansengaging the plate on the opposite side from said riser, said last namedmeans provided with means adapted to clamp said cap and said riser inthe desired position.

9. A bubble cap assembly according to claim '7 in which theseatingsurfaces on said riser are symmetrically and circumferentially spacedtherearound so that the spacing between said cap .and the base may bevaried by a partial rotation of said cap with regard to said riser.

10. A bubble cap assembly adapted to 'cover an opening in a plate,comprising a generally cylindrical riser seated in said opening, aplurality of inclined planes at the top of said riser, a cap for saidriser,'webs in said cap adapted to center it over said riser, and toseat on said inclined planes, a strongback for said opening below saidplate, and a bolt passing through said strongback :and said cap to clampsaid assembly together and to said plate.

11. A bubble cap assembly according to claim 10 in which said risertapers inwardly toward its

